Subjects will be admitted to the GCRC for 26 hours. Half of the subjects will be randomly assigned to a relaxation condition, with the first session beginning prior to the initiation of blister wounds. All participants will be followed after discharge to assess the healing of the blister wound sites. The aims of the study are: 1) to assess the linkages among dispositional optimism, expectancies, mood, hormones, and production of proinflammatory cytokines, as well as the extent to which relaxation, age, and gender mediate these relationships; 2) to determine the relationships between hormones and production of proinflammatory cytokines from peripheral blood and at the wound site, and the influence of age, gender, and relaxation on these pathways; 3) to assess relationships between proinflammatory cytokines from peripheral blood and blister chamber fluid and the healing of blister sites; and 4) to determine the extent to which age interacts with optimism and mood to impair cytokine secretion and wound healing.